Right now there is no way to do more than one route in a single activity. Sure you can freely navigate the map, but that will not give you the route badges.
I would like to be able to freely teleport to the start of any route on the same map.
Alternatively the option to combine a list of routes, so that when one route ended I will automatically teleport to the start of the next.
That would open up more creative options for e.g. the Everesting achievement or the long distance achievements.
Also: Bragging rights for doing Brevet style distances on Zwift.